<?php

function file_size_convert($bytes){
	$bytes = floatval($bytes);
	$arBytes = array(
		0 => array(
			"UNIT" => "TB",
			"VALUE" => pow(1024, 4)
		),
		1 => array(
			"UNIT" => "GB",
			"VALUE" => pow(1024, 3)
		),
		2 => array(
			"UNIT" => "MB",
			"VALUE" => pow(1024, 2)
		),
		3 => array(
			"UNIT" => "KB",
			"VALUE" => 1024
		),
		4 => array(
			"UNIT" => "B",
			"VALUE" => 1
		),
	);
	
	if($bytes == 0){
		return "0 B";
	}
	foreach($arBytes as $arItem){
		if($bytes >= $arItem["VALUE"]){
			$result = $bytes / $arItem["VALUE"];
			$result = str_replace(".", "," , strval(round($result, 2)))." ".$arItem["UNIT"];
			break;
		}
	}
	return $result;
}